EghtesadOnline: London would be resolute in defending its maritime interests in the Persian Gulf, but it does not want to escalate the situation with Iran, a British security source said on Thursday, after the United Kingdom claimed three Iranian vessels had tried to block the passage of a British tanker but backed off.

The source said the UK does not intend to escort every British-flagged merchant vessel through the Strait of Hormuz, although it had already raised its threat warning level for British ships in Iranian waters to the highest possible category earlier this week.

A British government spokesman said in a statement on Thursday that the "[Royal Navy warship] HMS Montrose was forced to position herself between the Iranian vessels and British Heritage and issue verbal warnings to the Iranian vessels, which then turned away," Reuters reported.

In Washington, two officials claimed that five boats believed to belong to Iran's Islamic Revolution Guards Corps approached a British oil tanker in the Persian Gulf on Wednesday and asked it to stop in Iranian waters close by, but withdrew after a British warship warned them, Financial Tribune reported.

One of the officials, who spoke to Reuters on condition of anonymity, said the British navy ship "pointed its guns at the boats and warned them over radio, at which point they dispersed".

"It was harassment and an attempt to interfere with the passage," the other official contended.

IRGC’s Dismissal

The IRGC denied the claim, saying that Iranian boats were carrying out their normal duties.

"Patrols by the IRGC's Navy vessels have been underway in the Persian Gulf based on current procedures and missions assigned to them," the Public Relations Department of IRGC Navy’s Fifth Naval Zone said in a statement.

It added that in the past 24 hours, there has been no encounter with foreign ships, including British ones.

Foreign Minister Mohammad Javad Zarif also dismissed as "worthless" the allegation, saying they have no value and are merely meant to create tensions.

Those who make such claims attempt to "cover up their weak point", he added.

The accusation came exactly a week after Britain seized an Iranian tanker in Gibraltar accused of breaking European sanctions by taking oil to Syria.

Iran strongly objected to "the illegal and unacceptable seizure" of its ship.

On Friday, Iran called on Britain to immediately release an oil tanker.

"This is a dangerous game and has consequences ... The legal pretexts for the capture are not valid ... The release of the tanker is in all countries' interest," Foreign Ministry Spokesman Abbas Mousavi said.

Mousavi also accused Britain of seizing the tanker under US pressure.

Washington blames Tehran for a series of attacks on shipping vessels in the Strait of Hormuz, the world's most important oil artery, since mid-May, accusations rejected by Tehran.